org.springframework.cloud.gateway.filter.WriteResponseFilter.java Source code

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Here is the source code for org.springframework.cloud.gateway.filter.WriteResponseFilter.java

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/*
 * Copyright 2013-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.springframework.cloud.gateway.filter;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.core.Ordered;
import org.springframework.core.io.buffer.NettyDataBuffer;
import org.springframework.core.io.buffer.NettyDataBufferFactory;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.web.server.ServerWebExchange;
import org.springframework.web.server.WebFilterChain;

import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.CLIENT_RESPONSE_ATTR;
import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.getAttribute;

import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import reactor.ipc.netty.http.client.HttpClientResponse;

/**
 * @author Spencer Gibb
 */
public class WriteResponseFilter implements GlobalFilter, Ordered {

    private static final Log log = LogFactory.getLog(WriteResponseFilter.class);

    public static final int WRITE_RESPONSE_FILTER_ORDER = -1;

    @Override
    public int getOrder() {
        return WRITE_RESPONSE_FILTER_ORDER;
    }

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
        // NOTICE: nothing in "pre" filter stage as CLIENT_RESPONSE_ATTR is not added
        // until the WebHandler is run
        return chain.filter(exchange).then(() -> {
            HttpClientResponse clientResponse = getAttribute(exchange, CLIENT_RESPONSE_ATTR,
                    HttpClientResponse.class);
            if (clientResponse == null) {
                return Mono.empty();
            }
            log.trace("WriteResponseFilter start");
            ServerHttpResponse response = exchange.getResponse();

            NettyDataBufferFactory factory = (NettyDataBufferFactory) response.bufferFactory();
            //TODO: what if it's not netty

            final Flux<NettyDataBuffer> body = clientResponse.receive().retain() //TODO: needed?
                    .map(factory::wrap);

            return response.writeWith(body);
        });
    }

}